Ventilated seating systems are widely known throughout several industries such as, for example, vehicle manufacturing, heavy machinery manufacturing, and agricultural machinery manufacturing. Ventilated seats are used in these industries to provide a cooling effect to a seated individual by drawing away perspiration. The removal of the perspiration results in an increase in comfort of the seated individual.
A somewhat similar effect can be obtained utilizing personal air outlets. Personal air outlets are currently utilized in automobiles and aircraft. Unfortunately, these devices only provide ventilation and cooling effect to specific surfaces of a body exposed to these ventilation devices. Generally, when personal air devices are utilized, the torso and legs can remain uncomfortable.
In the aircraft industry, the advent of in-seat electronics devices has resulted in an undesirable increase in heat load within the passenger cabin. For example, whereas an average passenger produces approximately 70 W of sensible heat, in-seat electronics may produce as much as 40 W of additional sensible heat per passenger. Other industries, such as those mentioned above, have similar thermal load challenges due to other factors.
Increasing the output of a local air conditioning system can offset this additional heat load. Unfortunately, this solution typically results in significant additional cost and weight, and requires additional power to operate.
Yet another solution involves utilizing a ventilated seating system. Ventilated seating systems typically provide comfort to the passenger by carrying away air that contains heat and evaporated moisture from the local area. This solution provides a decreased temperature within the local area.
One such type of ventilated seating system includes moving air through a portion of a seat cushion utilizing a pressurized duct or volume called a plenum. This ventilated seating system provides a negative pressure or vacuum and air is drawn into and through the seat cushion to the air plenum. Alternatively, if a positive pressure is applied, air is forced through and out of the seat cushion.
Another type of ventilated seating system includes moving air through a plurality of perforated plastic tubing members that are deposited within a seat base and a seat back and connected to air vents within the seat base and the seat back. The perforated plastic tubing members are aligned so that air passes through the perforations to corresponding air vents within the seat base and the seat back.
Unfortunately, moving air through a seat cushion or through vents within the seat back or seat base requires the use of a fan or other device to produce the necessary vacuum or forced air flow. The addition of a device for creating the necessary vacuum or forced air flow is undesirable because it adds cost and complexity, increases electrical and thermal loads, adds weight, and increases noise.
It would be desirable, therefore, to provide a system that would overcome these and other disadvantages.